This is the wheel I currently have on my R90/6. It came off a 1977 R100S. The drum wheels interchange for many years, not sure when they don't except you will run into problem if you try to use a cast wheel in place of a spoke wheel or try to use a /5 for a later wheel or vice versa. In the picture you are looking at the drive spline cup that is riveted to the wheel hub. These splines are in great shape I guess at least 80% good.

This is the wheel I took off my R90/6. It still has pretty good splines. I put this spline cup on this wheel about 12 years ago but the method I and my friend used to attach it was not correct. After 12 years one of the rivets let go. lucky I was only two blocks from home. It made a terrible noise and scrapped the rest of the way to my house but when I took it apart I found the broken rivet wedged against the brake shoe and making all the noise. I removed the broken rivet and continued riding later that week. When the second rivet broke about ten days later I decided to find my spare R100S wheel. I bought a new tire and everything's happy again.

This is a final drive unit as the same vintage as our bikes. Notice the drive splines here are on their last legs. They should look the same as those splines on the wheels. Drive splines on the final drive and the wheels are bumps and valleys. When new the bumps an valleys are the same size, roughly. As they wear the valleys get larger and the bumps get smaller. When the bumps are this pointy they are finished. You might make it home if you found this situation out on the road but it is really something that is supposed to never happen if you are paying attention. There was a rider only a couple years ago got stranded several states from home because he bought an Airhead and tried to cross the country on it because he heard that theses bike can cross the country. Happened on a different list I think. We explained that these bikes will cross the country after you have replaced every part on them.

Now you know. You will clean and lubricate the drive splines of the wheel and the final drive every time there is a new tire installed or the wheel is off for any other reason. I use coffee stirrer wooden sticks to scrape clean, you have to reach inside to get the old grease out, and sometimes I use a little cotton swab action. A little brake cleaner also helps but it is not something that has to be all that clean. Just get the majority of old grease out.

The grease to use here is Honda Moly 60. Not a lot is needed or desired. but you do have to get some in each valley and it is a little finicky to get much of it all the way inside. i like to slide the wheel on, wiggle it back and forth then remove to look at what sort of distribution I have.

If you over grease the splines the excess will be forced out and spun by centrifugal force on the brake hub where it will lubricate the brake pads. Something to avoid.

The connection of the drive shaft to the output flange of the transmission used those longer bolts with washers up through 1980. In 1981 BMW came out with the short bolts. Those working on their older than 1981 machines may use the shorter bolts. You can not just use the longer bolts and leave the washers off. They will contact the transmission rear seal and cause trouble. If you used the long bolts your supposed to get new washers, in fact BMW wants you to use new bolts also. So just use the short bolts. If you used the long bolts with washers you will also likely find more broken washers when it gets taken apart some day. At a dealership parts counter some may try to sell you the long bolts and washers. Don't go there. In fact if that happens try not to laugh too much in the guys face. But insist the short bolts are what you want. (most of them know this but you never know, ya know?)

26 11 1242 297 Short Bolts

If the rubber boot is cracked it may need replacing. Judgement call maybe but a pain to replace later if you don't replace a cracked one now.

33 17 1 230 304 Rubber Boot

The long hose clamps are usually good but sometimes one gets a screw messed up or have another problem.

33 17 1230 297 Long Hose Clamp

There's a paper gasket between the swing arm and the final drive. Not expensive. The old one may work but here's the # for a new one.

33 17 2 311 098 Gasket

There are many places there may be some problem nut most things go back together like other machines. Pay attention to screw and stud threads. Damaged threads should be repaired or replaced.

Finally I have to yell a little bit. This happened only one month ago. Another newcomer was doing a rear main seal and several of us told him to BLOCK the CRANK. Well his excuse was that he never paid attention to anything that didn't make sense and since he didn't know what we were talking about he ignored the advice.

Failure to BLOCK THE CRANK may lead to several thousand dollars damage to your bike.

Our friend last month got off easy. But it doesn't always end this way. Failure to block the crank can and does destroy the engine bottom end the the whole thing has to come apart to repair.

Please write that you understand this and have taken care of Blocking the front of the engine crankshaft.

I wrote that up last night on my phone but it didnt post for some reason. Yes I went out today and blocked the crank with a small towel and really jammed it in there super tight and secured the front cover down. THen I went and removed everything but the flywheel. I have all of the non reusable bolts out but I cant pull that flywheel out. That is common, I assume? I tried screwing the long bolts in there and then yanking on them (fairly hard) to the point where my gut said to stop and ask what's going on. I kind of tapped along the edges with my rubber mallet. I could get it to wiggle a bit but not come free. I am following the Clymer steps so I did mark everything as far as making sure it goes back in on TDC matching with where it should on the crank. Can you imagine if you didnt do that? ha! Well I'm almost out of here until Monday if you don't hear back that is why. Thank you for the effort to show me the splines, that is awesome! Oh, I do have every intention of crossing the country on this thing too, when it is ready. That is my ultimate goal with this thing. Not to make it look pretty (well not goal #1 at least) but I have some very long rides on the schedule for this bike. (A 2000 ride mid summer to the Mississippi Delta region, a 1500 mile ride in September 2014 around Lake Superior (This year I'm taking the HD), and I'd love to try a big 6000 mile ride with my buddy in his proven 76 GL1000 to an undisclosed location. But we may have to wait a couple years on that one to get enough time from work built up. I mention that because it may change some of your advice? Maybe not.

Here is the tool I used to hold the flywheel in place. It did not leave any marks after I was done but I've got some steel laying around so I'll actually make a correct tool. Yes I know I was most likely tempting fate and lucky I didnt mess up any of the flywheel threads but nothing bad happened.

I use a really old puller that I've had for years. It is a Plomb 4010 puller. It has the 11.5" yoke, #4011. The number on the yoke is how you spot it. The nice thing about this puller is it is the yoke is long which is what you need to pull the flywheel off.

This picture in not my puller but one just like it. This picture also only shows the hook arms used for pulling and not the bolt arms which is what you need.

Another puller may be found to do the job. Just remember the flywheel is pretty wide and you need a bolt puller like a steering wheel puller but a steering wheel puller is too narrow. Same thing for the vibration dampener puller, too narrow.

Cycle Works makes a puller for this;

They sell this for $26. The Plomb puller I showed earlier goes for $70 to $100 on Ebay but the bolt puller arms are rare.

Finally I have gotten the flywheel off by rocking it but don't think it is good for the thing. Try to use a puller. You may find a spacer and you may find an O-ring under the flywheel. I don't know what year these changes start.

These are the 10mm bolts. The short ones are earlier than the long ones but some cranks are drilled for long bolts even if they have short ones in them. Either version of the 10mm bolts gets changed every time.

These are the 11mm flywheel bolts. The 11's are what you should have. They are not always changed by some mechanics but you probably should change them.

When I did the clutch on my bike several years ago I found the bolts holding the pressure plate on were a mess. None of them threaded in smoothly. I changed these 6 bolts even tho they were not required but the new ones fit and held so much better.

Those splines on their last legs? Those splines were junk a long time before that photo was taken. BMW's have enough drive line slop without running splines like that! Talk about making you rubber cow more rubbery. Extremely excessive drive line lash will do that!

Since when does anyone need a flywheel puller for BMW's. I have removed a lot of flywheels and have never needed one. I have never seen any of the other mechanics I have worked with need one either? What gives?

I didnt trust it to ride down the road so I'm just bombing around the yard. As I said it did run good and shifted fine (normally doesnt grind like that going into first that was my mistake you can see my reaciton) but quite a bit of metal on the plug. Anyway the starter seems to grind on the last split second, when the engine catches and you can almost pic that up in the video. That is another project, another day. Regarding the splines, they look fine to me, right?

Also, from looking at the picture on the first page of this thread and the video can you guys tell what bars I have? I hear a lot about these "low Euro bars" and I might replace mine because they are so rusted and was curious which ones I had. I am assuming they are stock US.

I forgot to add that I don't need any kind of flywheel stay for loosening or tightening the flywheel bolts either. I just get one of my pry bars and let it jam between the flywheel and the case down at the bottom where the bell housing has that relief for the oil pump and whatnot. I have done tons thusly. It doesn't hurt the starter teeth or mark the case.

I always feel guilty if I rock the flywheel off the crank but SS says it's OK so I won't feel bad any more if I have to do that. Still I have a nice puller for the job and may as well use it. I think I did some damage to this tool a few years ago in pulling a pinion flange off a Ford but it still has plenty of strength to do BMW flywheels.

I say those splines on you final drive are about half way worn through. Notice the difference in width of the valleys as opposed to the bumps? The wheel splines look a little better. You are going to have to keep an eye on it. But I'd say there's no danger for at least several years. Mileage dependent of course.

Look at the third photo from the top. You can see into the back of the spline area and there is the unworn area in back. Spend some time cleaning the splines and you will get to know them. After this is back together you can rotate the wheel against the final drive with the trans in gear and see how much free play there is. It will be quit a bit.

I think some others may give you a worse estimation than I have but let's see what the consensus is.

I have made much more noise and gear clashing sounds at times than you did. In fact your bike sounds better than mine in general too. Next thing you know you'll be mounting knobby tires for that off road track behind your house.

Pretty sure that is a USA bar. They are pretty comfortable I think. Some want a narrow sportier look but the USA bar works for a lot of riders. You can sit up easier with that bar so it is more comfortable on long distances.

Charlie,
Ok I see what you mean now. I was thinking in my head (even though you explained it right) that I should be comparing the height of the bumps. I looked at pictures of new splines from Hucky's and can see what you are referring to., the distance between them. Yes there is a tiny bit of play that I remember when I had it together. I will start a different thread here that will document "everything" I've been doing after I get this tranny issue done. So far everything has been a "win." I told the folks at the wedding it was almost like it "wants" to be fixed up. Ok I'll update when I have all that stuff cleaned up and re-lubed, and after I somehow get the flywheel out. Also I will inspect the friction plate and clutch parts

And then I suppose I'll ask what gets looked at next after I'm in that far.
Nathan

You may find info by using Goole Search. And there are the standard sources. I gave you Anton's pages earlier. Have you become familiar with Snowbum yet? He gets criticized for a bit too much wordiness but he does have the info. I always turn to Snowbum first for torque values and most any other numbers.

There are several other areas to look at while the trans is away. The swing arm bearings should be removed and cleaned so new grease can be installed. Don't take the races out unless any of the bearings show dark shadows and need to be replaced.

I think you took the through out pieces all out of the trans before it was shipped? The long rod with the felt should not have mushrooming on either end. (BTW don't take the felt off. the old one will work better than a new one unless extremely worn).

There is the small roller bearing which I think should be replaced as a general rule. (this time, new trans, new bearing) It is not cheap but it can take the entire rear cover with it if it blows and they are hard to judge. I put a new one in when I put the current trans in.

The two thrust pieces. I might have to change these in the next couple of weeks. I'll try to remember to take pictures. They will get pitted or show other surface imperfections if they are going. A little discoloring is probably OK.

The throw out arm that is held by the pin on the back of the trans. Pins get scored because nobody greases them. The boss the pin is in should fit nicely. The E-clip holding the pin in place must be in good shape.

Some riders replace the pin with a bolt and a Nylock nut because it seems more secure. I have never had trouble with the OEM system unless I wasn't paying attention when I put it together.

The rear wheel itself has a complicated bearing set up. This part can always be tended to at a later date but we should probably cover it before you get the trans back. Lots of time.

I forgot to add that I don't need any kind of flywheel stay for loosening or tightening the flywheel bolts either. I just get one of my pry bars and let it jam between the flywheel and the case down at the bottom where the bell housing has that relief for the oil pump and whatnot. I have done tons thusly. It doesn't hurt the starter teeth or mark the case.

I sure got a bunch of flak when I said that exact same thing several years back - about jamming a screw driver between the teeth and the bell housing to hold the flywheel.

If you do it right, there isn't much strain on the teeth anyway. You can apply torque to the socket that counteracts the rotation - the two forces just about cancel out.